Earlier, a Covid-infected medical staffer at the hospital's Kanchanaphisek Medical Centre had said on social media that the Sinovac vaccine could not protect him from getting infected.
In a bid to prevent confusion on the vaccine's efficacy among people, Assistant Professor Dr Naris Kitnarong, the hospital's deputy dean of corporate communication and social responsibility, said the medical staffer had received the first dose on April 7.
He suspected that the staffer had tested positive for Covid-19 on April 17 because he had dined at a crowded place on April 12, five days after receiving the first dose.
"The medical staffer had contracted Covid-19 because the staffer had gone to a place at risk of infection. Meanwhile, the staffer had not received the second jab yet," he said
He added that the medical staffer had posted a message apologising for the misunderstanding on April 25.
He asked people to get their Covid-19 vaccine jab.
"Many studies have shown that getting a vaccine is necessary because it can protect people from infection, as well as reduce the severity of the disease if infected," he added.